Pet projects are not necessarily good for a company: 1) Code is not necessarily an asset, it is also a liability: needs to be maintained, tested, documented, e

Pet projects are not necessarily good for a company: 1) Code is not necessarily an asset, it is also a liability: needs to be maintained, tested, documented, etc. This has a non-trivial cost. 2) Engineer salaries are usually more expensive than a license. 3) Experience working using internal frameworks/libraries/etc can be harder to trade in the marketplace, especially if you are not the author. 4) It is hard to keep up feature parity with commercial/open source alternatives. 5) Internal projects do not necessarily lead to more employee satisfaction. They can be usually lacking around user experience and can be frustrating to use. 6) Some internal projects have purely political motivations, like self-perpetuating the authors in the company. Finally, if you absolutely require to start an internal project, but it does not provide a competitive advantage: open source it.